The war was not really about the bog. It was about religion, family pride, and an English king who could not abide being defied. Henry VIII had broken from Rome a decade earlier, dissolving the monasteries and lining his treasury with their riches. He wanted his nephew James to do the same in Scotland. James wrote to Pope Paul III on 9 November 1542, explaining that he had defied Henry's pressure and could fund his own resistance because, unlike Henry, he had not stripped the Church. The Earl of Angus added that Cardinal Beaton and the Earl of Moray had even planned to march their own force across the East March behind the main Scottish army and serve a papal interdict in English churches. The mood was high and confident. The muster order survives, listing the routes by which the contingents were to march - from Dumfries through Hoddom and the Kirkconnel tower at Ecclefechan; from Peebles down to Moffat; from Selkirk by way of Eskdalemuir.

What happened next depends on which witness you trust. Lord Maxwell had said he would lead the attack in person, though he had not been formally appointed commander. A later report by George Douglas of Pittendreich - who was not actually present - claimed that, in Maxwell's absence, Oliver Sinclair, James V's favourite courtier, climbed onto a soldier's shield and declared himself the king's chosen commander. The other Scottish lords, in this account, refused to accept him, and the army's command structure dissolved on the spot. The English commander Sir William Musgrave, who was there, said Maxwell was in fact in charge, fighting on foot with the rest of the dismounted nobles on the bank of the Esk. Whichever account is right, the Scottish force met Lord Wharton and his three thousand Englishmen near Solway Moss and could not organise itself into anything resembling a battle. After an initial cavalry skirmish at Akeshawsill, the Scots moved 'down' towards Arthuret Howes and discovered they had penned themselves in between the river and the bog, on English soil, with no way out.

The historian Gervase Phillips estimates that only about seven Englishmen and twenty Scots died in the fighting itself. The horror was the rout. Several hundred Scotsmen are believed to have drowned in the peat-moss and the river as they tried to escape - sucked under by the bog or swept off by the current of the Esk, weighted with armour and panic. A Scottish writer of the period summarised the disaster bitterly: the Scots were 'beguiled by their own guiding.' They had walked into a trap of their own making. Twelve hundred Scottish prisoners were taken to England. Ten field guns surrendered with them, including four falconets cast with the cipher 'JRS' for Jacobus Rex Scotorum - James, King of the Scots - and the Scottish royal arms beneath an imperial crown. The captured men were taken first to Carlisle, then on to Newcastle and London. The Privy Council ordered that Scottish prisoners entering London should wear a red St Andrew's cross sewn to their clothing - a humiliation calibrated by clerks.

The diplomatic afterlife of the battle reads like a slow, sad pageant. Eustace Chapuys, the imperial ambassador, recorded that the Scottish prisoners attended Henry's Christmas court still wearing swords and dirks, were able to speak with the French ambassador, and each received a gold chain from the English king as a present. The grandeur was strategic. Henry hoped these noblemen, once ransomed back to Scotland, would carry English influence home with them. Some of the higher-ranking captives were exchanged for hostages - called 'pledges', often their own sons or brothers - at Carlisle on 10 January 1543. Others were prevented from returning by their own Scottish government, which accused them of treachery for having lost the battle; their families were arrested at home. Three weeks after the battle, on 14 December 1542, James V died at Falkland Palace. He was thirty. The news of Solway Moss is believed to have hastened his end. His daughter, born just six days before his death, was Mary, Queen of Scots. She would inherit the consequences of this defeat for the rest of her life.

Solway Moss now lies under farmland and slow-running burns just north of the M6 and west of the A7, the battlefield registered by English Heritage and under consideration by Historic Environment Scotland for inscription on the Scottish inventory. There is no obvious monument. The ground is flat and reedy. The peat that swallowed soldiers in 1542 is still there beneath the topsoil. The historian Marcus Merriman has argued that the disaster was less the start of Henry VIII's later 'Rough Wooing' than the unhappy ending of James V's own war - that the capture of so many Scottish lords at exactly the moment Mary was being born did not really change Henry's policy, and that the Scottish lords themselves rejected the Treaty of Greenwich a year later. The names of the dead remain mostly anonymous. The names of the captured run to a long list of earls and lairds: Cassilis, Glencairn, Maxwell, Somerville, Fleming, Sinclair, Maitland of Awencastle. Behind each title was a man, taken from a Dumfriesshire muster point and led south through Carlisle to a chain and a chamber and, for many, a return so politically poisoned they could not go home again.